express-graphql-schema-router

A package to route users to different GraphQL servers. Uses Express, ApolloServer, and graphql-http-proxy. Allows for custom filtering in each schema, and is reflected in what users see in GraphQL Playground.

Installation

npm i express-graphql-schema-router

schemaRouter({ entryPoints, path, router })

Options

entryPoints: <Object> (required)

• A map of ApolloServer options

path: String (required)

• Path to serve GraphQL from. Equates to app.use(path, ...)

router: <Function> (required)

• Function which returns key of schema corresponding to ApolloServer options from entryPoints to route the response to

Example

const express = require('express');
const jwt = require('jsonwebtoken');
const parseBearerToken = require('parse-bearer-token').default;
const { schemaRouter } = require('express-graphql-schema-router');
 
const app = express();
 
...
 
const entryPoints = {
  public: {
    schema: publicSchema,
    context
  },
  authenticated: {
    schema: authenticatedSchema
    context
  }
};
 
app.use(...schemaRouter({
  entryPoints,
  path: "/graphql",
  router: (req) => {
    let route = "public";
    let token = parseBearerToken(req);
    if(token) {
      try {
        let test = jwt.verify(token, secret);
        if(test !== undefined) {
          route = "authenticated";
        }
      } catch(e) {}
    }
    return route;
  }
}));
 
app.listen("3000", () => {
  console.log("Listening on port 3000");
});
 

filterSchemaRouter({ schemaMap, options, path, router })

Options

schemaMap: <Object> (required)

• Map of schema keys to baseline and typeMap

  • typeMap: <Object> (default: {})

  • baseline: <Object> (default: graylist)

  ###### whitelist

  Allow root fields, allow object fields

  ###### graylist

  Deny root fields, allow object fields

  ###### blacklist

  Deny root fields, deny object fields

Example:

{
  public: {
    baseline: graylist,
    typeMap: {
      Query: {
        field1: true
      }
    }
  },
  authenticated: {
    baseline: whitelist
  },
}

options: <Object> (required)

• A map of ApolloServer options

path: String (required)

• Path to serve GraphQL from. Equates to app.use(path, ...)

router: <Function> (required)

• Function which returns key of schema corresponding to ApolloServer options from entryPoints to route the response to

Example

const express = require('express');
const jwt = require('jsonwebtoken');
const parseBearerToken = require('parse-bearer-token').default;
const { filterSchemaRouter, whitelist, graylist } = require('express-graphql-schema-router');
 
const app = express();
 
...
 
const publicTypeMap = {
  Query: {
    public1: true,
    public2: true
  }
};
 
const schemaMap = {
  public: {
    baseline: graylist,
    typeMap: publicTypeMap
  },
  authenticated: {
    baseline: whitelist
  }
};
 
app.use(...filterSchemaRouter({
  schemaMap,
  options: {
    schema,
    context
  },
  path: "/graphql",
  router: (req) => {
    let route = "public";
    let token = parseBearerToken(req);
    if(token) {
      try {
        let test = jwt.verify(token, secret);
        if(test !== undefined) {
          route = "authenticated";
        }
      } catch(e) {}
    }
    return route;
  }
}));
 
app.listen("3000", () => {
  console.log("Listening on port 3000");
});
 

filterSchema({ schema, typeMap, baseline })

Filters fields available in a schema based on a typeMap and baseline. Returns the filtered schema.

Options

• schema: GraphQL Schema (required)

• typeMap: <Object> (default: {})

• baseline: <Object> (default: graylist)